Koltun, 44, is on trial in the Nov. 4, 2010 slayings of Gerald Piscopo, 28, and his uncle Francis Piscopo, 49, both of Highland, at a vacant house in the City of Newburgh.

Defense lawyer Glen Plotsky has argued that Koltun feared Francis Piscopo and hired two men to protect him. The men then shot the Piscopos on their own, Plotsky said.

Senior Assistant District Attorney David Byrne called Samuel Kisin of Coney Island to the stand Tuesday.

Kisin testified that, in 2009, when his car wash and quick lube business were struggling, a friend introduced him to Koltun as someone who was successful in real estate. Kisin said he thought he could learn something about the business.

Kisin said the rabbi convinced him to act as a broker, soliciting potential investors for hard-money loan deals Koltun wished to put together, with properties Koltun said he owned as collateral. It was difficult to find investors, Kisin testified. He said people he contacted told him there were liens on the properties, or it wasn't clear who the actual owners were.

In August 2009, Kisin found a potential investor for a $1.3 million deal. The investor wanted the three collateral properties insured. Kisin said Koltun borrowed $20,000 from him for the insurance. Shortly before the deal was to close, Kisin said, Koltun asked for another loan of $20,000 to pay his children's tuition, alimony and other personal expenses. Thinking he would be repaid that money on top of his $150,000 commission when the deal closed, Kisin said, he made the loan. The deal fell through because of problems with the properties, Kisin said. Koltun put him off when he asked for repayment, Kisin said, and stopped returning calls in late 2009 and early 2010.

In early 2010, Kisin said, he was having lunch with "Big Frank" (Francis) Piscopo, a customer at his father's auto repair shop, and happened to mention his problems with the rabbi. Piscopo offered to help him collect the debt, Kisin said. Kisin never recouped any of the $40,000 he loaned Koltun. "Not a dollar," he said.

Plotsky asked Kisin if he was licensed as a financial analyst or broker. Kisin replied that he didn't know licensing was required. The trial resumes Wednesday.